Travel photographer Brendan van Son was at a recent media Q&A with Hadfield and asked him about his setup. Hadfield explained that his secret is working in zero gravity: Whereas on Earth a 400mm camera would necessarily be heavier in the lens, and the photographer would have to constantly account for that slight gravitational pull, in space he can just let the camera float in zero-g without any need for tracking. Not having to constantly adjust the camera means that astronauts taking photos in space are even able to take freehand, long-exposure photos at night.

In fact, there’s only one limiting factor, Hadfield explained: “In space, the only [thing] you really have to think about is your heartbeat, because just the pulse of your heart will make the camera [tilt].”